/*
 * Copyright (c) 2004-2022, University of Oslo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors 
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.hisp.dhis.analytics.event.data;

import java.util.Optional;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.RequiredArgsConstructor;
import org.apache.commons.lang3.StringUtils;
import org.hisp.dhis.system.util.SqlUtils;

@Getter
@RequiredArgsConstructor(access = AccessLevel.PROTECTED)
class ColumnAndAlias {
  public static final ColumnAndAlias EMPTY = ColumnAndAlias.ofColumn("");

  protected final String column;

  protected final String alias;

  static ColumnAndAlias ofColumn(String column) {
    return ofColumnAndAlias(column, null);
  }

  static ColumnAndAlias ofColumnAndAlias(String column, String alias) {
    return new ColumnAndAlias(column, alias);
  }

  public String asSql() {
    if (StringUtils.isNotEmpty(alias)) {
      return String.join(" as ", column, getQuotedAlias());
    } else {
      return column;
    }
  }

  public String getQuotedAlias() {
    return Optional.ofNullable(alias).map(SqlUtils::quote).orElse(null);
  }
}
